A novel paclitaxel-eluting porous carbon–carbon nanoparticle coated, nonpolymeric cobalt–chromium stent: Evaluation in a porcine model

Abstract

Objectives: We aimed to evaluate the response of porcine coronary arteries to a novel paclitaxel‐eluting porous carbon–carbon nanoparticle coated, nonpolymeric cobalt chromium stent. Background: Polymer based drug‐eluting stents significantly reduce restenosis. However, the indefinite presence of polymer is thought to initiate and sustain inflammation and contribute to the occurrence of late complications. Methods: Sixteen carbon–carbon coated, nonpolymeric cobalt chromium stents with two different doses of paclitaxel (eight of each) were implanted in porcine coronary arteries. In addition, eight cobalt chromium stents coated with a biodegradable polymer were also studied. Animals were sacrificed 6 weeks after stent implantation and histomorphometric analysis was performed. Results were compared among the three groups of stents. Results: The cobalt chromium stents coated with carbon–carbon with low and medium doses of paclitaxel both showed acceptable performance characteristics, with respect to endothelialization, neointimal hyperplasia, percentage diameter stenosis, inflammatory response, and tendency to fibrin deposition, when compared to historical data with the Cypher stent. On the other hand, the stents coated with poly(lactide) and poly(lactide‐co‐glycolide) biodegradable polymers and 0.7 μg/mm² paclitaxel showed poor performance. There was a significant tendency to poor endothelialization, greater neointimal hyperplasia, percentage diameter stenosis, greater inflammatory response, and tendency to fibrin deposition (P < 0.01 for all parameters). Conclusions: This preclinical evaluation demonstrates the safety and efficacy of a novel cobalt chromium stent with a carbon–carbon coating and low and medium doses of paclitaxel.